The desire to understand and analyze complex chemical and biological systems has led to the development of analytical techniques that employ parallelization and miniaturization of analyte processing, e.g. Graber et al, Current Opinion in Biotechnology, 9: 14-18 (1998); Fodor et al, Nature, 364: 555-556 (1993); Meier-Ewert et al, Nature, 361: 375-376 (1993); Taylor et al, Nucleic Acids Research, 25: 3164-3168 (1997); Garner et al, BioTechniques, 14: 112-115 (1993); Lam et al, Nature, 354: 82-84 (1991); Ohlmeyer et al, Proc. Natl. Acad. Sci., 90: 10922-10926 (1993); DeRisi et al, Science, 278: 680-686 (1997); Wodicka et al, Nature Biotechnology, 15: 1359-1367 (1997); and the like.
Many of these techniques employ microparticles for synthesizing analytes or for capturing analytes for subsequent analysis, e.g. Lam et al (cited above); Benkovic et al, International patent application PCT/US95/03355; Gavin et al, International patent application PCT/EP97/02039; Brenner et al, International patent application PCT/US96/09513, and the like. Even though the properties of different types of microparticles can vary widely, microparticles generally facilitate the construction and manipulation of large repertoires of analytes with minimal reagent and/or sample consumption. However, handling and manipulating large numbers of microparticles, e.g. tens to hundreds of thousands, for carrying out specific chemical and/or biochemical analyses gives rise to many difficulties, including whether sufficient signal is generated on individual microparticles for detection, how to track individual microparticles through multiple steps of a process, mechanical strength of microparticles under pressure or flow conditions, the ability to uniformly deliver reagents to microparticles for carrying out steps of an analytical process, whether clumping or other inappropriate interaction of microparticles and/or reagents occurs, the degree to which analytes and/or processing reagents adsorb onto vessel walls, whether protein reagents or analytes denature causing a disruption of reagent distribution and access, whether adjacent microparticles will interact, e.g. to degrade or obscure a signal or to inhibit reagent access, and the like.
In view of these difficulties, it would be desirable to provide a system and apparatus for handling and processing multiple solid phase supports, such as populations of microparticles. It would be especially desirable if such system and apparatus permitted the tracking and analysis of multiple analytes anchored to separate microparticles through a sequence of several processing and/or analysis steps.